Electric generator



mm REFERENCF SHRCH WM 3,1455%212 QLUll May 12, 1964 s. SZEKELY ELECTRICGENERATOR Filed Dec. 30, 1959 United States Patent 3,133,212 ELECTRICGENERATOR Steven Szekely, 645 Lelferts Ave., Brooklyn 3, N.Y., as-

signor of twenty-five percent to Louis M. Friedman and twenty-fivepercent to Karl F. Ross, both of New York, N.Y.

Filed Dec. 30, 1959, Ser. No. 862,828 4 Claims. (Cl. 3104) My presentinvention relates to a system for generating electric current.

It is an object of my invention to provide an improved system for thethermal generation of electric current.

It is another object of the invention to provide an electro-generatingsystem obviating major mechanical losses and adapted to make use ofexisting high-temperature heat sources.

A more particular object of this invention is to provide means forimproving the efficiency of an electric generator of themagnetohydrodynamic type.

A feature of my invention resides in the provision of an electricgenerating system, operating by a thermodynamic cycle, in which the heatcontent of a high-temperature fluid (preferably a vapor), rendered atleast partially conductive by the presence of electrons producedexternally thereof, is converted to kinetic energy whereby theconductive fluid may be passed at a relatively high velocity through amagnetic field to generate the electric current.

3,133,212 Patented May 12, 1964 heat content of the fluid and may bedispensed with should a closed thermodynamic cycle be undesirable. Thus,the invention may be utilized effectively for the generation of electricenergy from a rocket or jet exhaust; the hot exhaust gases may beexposed to an electron cloud in order to increase the conductivity ofthe exhaust which is then passed between the electrodes of a generatingchamber. After the negative charge is stripped from the fluid whosekinetic energy has been utilized to increase the velocity of the chargecloud, the waste fluid may be released since no recirculation will benecessary.

The bombardment of a vapor with charged particles (electrons) in thesystem of my invention converts it, in effect, into a plasma-like fluidat temperatures materially below thos'e 'usedfor the production ofplasmas in conventional magnetohydrodynamic generating systems. Thepresent system may, however, also be used in otherwise conventionalmagnetohydrodynamic systems to accelerate the formation of plasmas bythermally induced autoionization, and to increase the conductivities ofplasmas originally containing substantially equal numbers of positivelyand negatively charged particles.

The above and other objects, features and advantages of my presentinvention will become more readily apparent from the followingdescription, reference being made to the accompanying drawing in which:

FIG. 1 is a somewhat schematic side-elevational view, partly in section,of a generating system according to According to another feature of theinvention, the electhe invention; ei flnLatu giyilmm-anmittemdisposewong-thk FIG. 2 is a cross-sectional view takenalong line II-II w ath f the fluid. A thermionic emitter, heated toelectron-emission temperature preferably by the high-temperature fluidprior to the release of its potential energy, may be convenientlyutilized in the system. The negatively charged particles entrained bythe fluid may be magnetically deflected onto a suitable collector toproduce a potential difference between the latter and a counterelectrodebetween which there will thus pass an electric current. The conductivefluid may be caused to move within the transverse magnetic field at aconsiderably increased velocity as a result of the partial conversion ofits heat content to kinetic energy.

Still another feature of the invention resides in t entrainment ofthermionically emitted negatively charged particles by the vapor stateof a fluid through a Venturi nozzle as the fluid is injected underpressure into a generating chamber, having a substantially lowerpressure, wherein the fluid carrier and the entrained negative cloudmove past one or more collector electrodes toward which the negativelycharged particles are then directed by a magnetic deflecting field whoselines of force run substantially perpendicular to the fluid path.

According to a more specific feature of my preseh invention, a fluid ofrelatively high conductivity and, preferably, large collisioncross-section (e.g. sodium or mercury) is heated by suitable means (afurnace or a nuclear reactor) and passed through a toroidal chamberwhose inner wall is provided, on the outer surface thereof, with athermionically emissive layer (e.g. a metal oxide), thereby raising thetemperature of that layer to or above the point required for electronemission. The hot fluid is then passed through a Venturi nozzle openinginto the generating chamber which is provided with return tubesconducting a portion of the fluid behind the Venturi nozzle whereby thefluid is recirculated to entrain the emitted electrons, at a relativelyhigh velocity due to its rapid expansion at the nozzle, to the region ofthe collector electrode or electrodes. The fluid vapor is then condensed or compressed and recirculated to the heating station to completethe thermodynamic cycle. The liquefaction stage serves only to removethe residual, unusable originating at the high-temperature source 10 andadapted to conduct a hot fluid, preferably a vapor under pressure,through a toroidal shell 22 and thence via a pipe 23 and a Venturiinjector nozzle 24 through the center of the torus into a generatingchamber 25. The toroidal shell 22 is surrounded by a low-pressurechamber 26 provided with apertures 27 which communicate, via returntubes 28 terminating in apertures 29, with the interior of generatingchamber 25 at a location downstream from the injector nozzle 24. Theouter s urface of inner wall 30 of shell 22 is provided with a layer 31of a thermionic electron emitter, such as lanthanum borohydride, metaloxides and the like, adapated to be raised to the emission temperatureby the heated fluid traversing shell 22. The mouth 32 of injector 24opens into the generating chamber 25 at a point just beyond the emitterring to prevent chilling of layer 31 by the expansion-cooled fluid atthe injector mouth. The generating chamber 25 houses a pair of collectorelectrodes 33, 34 and a pair of counter-electrodes 35, 36 (see also FIG.3), opposite the collector electrodes, between the poles 37 and 38 of aconstantflux magnet 40.

Generating chamber 25 is provided with an outlet pipe 41 forming a fluidpath between the latter and the lowtemperature sink 50 which,advantageously, is a condenser having an inlet 42 and an outlet 43 for acirculating coolant. Condenser 50 is fitted with a pipe 44 connectingthe latter with the fluid-circulating pump 51 which discharges via apipe 45 into the high tempera ture source 10. The path of therecirculated fluid may, as shown in dot-dash lines, include aregenerative heating stage 60 wherein a portion of the residual heatcontent of the fluid streaming toward the condenser 50 may be utilizedto preheat the condensed fluid before the latter is admitted to the mainheater l0. Condenser 50 serves to maintain a partial vacuum in chamber25.

In operation, a preferably conductive fluid, such as liquid sodium ormercury, is heated within the high-temperature source to temperatures inexcess of the temperature required for thermionic emission from layer31. The resulting vapor is then passed through the toroidal shell 22 viapipe 21 so that the layer 31 commences thermionic emission. The emittedelectrons tend to accumulate and form a negatively charged electroncloud in the vicinity of layer 31, this cloud mingling with fluidparticles drawn off from the vapor stream at apertures 29 andreintroduced thereto via return tubes 28. This portion of the fluidenters reduced-pressure chamber 26 and is then siphoned through thecentral opening of the shell 22 into the chamber 25, entraining thenegatively charged particles. As the fluid passes through the centralopening, its negatively charged particles are swept into the generatingchamber 25. The carrier fluid travels with a relatively rapid motiontoward the electrode pairs 33, 35 and 34, 36 by reason of the highvelocity of the vapor stream emanating from the mouth 32 of Venturinozzle 24. The charged particles are then deflected toward collectorplates 33 and 34 by the transverse magnetic field created by the poles3'7 and 38. The fluid, stripped of its entrained negative charge, isthen condensed in the heat sink 50 and recirculated to thehightemperature source 10 by pump 51, to recommence the thermodynamiccycle.

In FIG. 3 I show the collector electrodes 33, 34 connected in parallel,for maximum current, to a load 47 which is connected to the potential ofemitter 31 (i.e. ground) through the slider 48 of a potentiometer 4Q.Counter-electrodes 35, 36 are connected in parallel to the otherterminal of the resistor 49. It will thus be apparent that the emitter31 will be at a potential intermediate that of electrodes 33, 34 and 35,36, and that the current flowing through the load 47 will depend on therate of electron collection at electrodes 33, 34. The current flow willbe a function of the emission rate and of the vapor velocity. Thepositive potential induced on electrodes 35, 36 maintains the net chargeat the center of the magnetic deflection field substantially at or nearzero to prevent the accumulation of a negative space charge which wouldoppose the entry of further electrons into this region.

Owing to the non-linear deflection of the charged particles by themagnetic field, it will be seen that one collector (e.g. electrode 33)may be positioned to receive a greater negative charge than an adjacentelectrode (e.g. electrode 34). The potential difference betweenelectrode 33 and ground will thus be greater than that between electrode34 and ground when the two are disconnected. A plurality of suchelectrodes, spaced along the fluid path, may therefore be provided totap the generator at different voltages and/or power outputs. It is alsopossible to utilize the potential drop between these electrodes toenergize a load, e.g., as indicated at 47 in FIG. 3.

For maximum utilization of the heat content of the fluid, the latter maybe initially heated to a temperature such that, on leaving thegenerating stage, it has a temperature in the vicinity of its boilingpoint.

The generating system illustrated and described admits of manyvariations and modifications readily apparent to persons skilled in theart and intended to be included within the spirit and scope of myinvention, except as further limited by the appended claims.

I claim:

1. In an electric-current generator, in combination, a generallytoroidal shell having an inner peripheral wall of thermally conductivematerial forming a central chamber, said wall being provided with anelectron-emissive layer in said chamber, conduit means having anincoming branch and an outgoing branch opening into the interior of saidshell, said conduit means further including a duct forming an extensionof said chamber, said outgoing branch terminating in a nozzle extendinginto said chamber along the toroidal axis of said shell in spacedrelationship with said layer, a source of gaseous fluid connected tosaid conduit means, heating means adjacent said conduit means forbringing said fluid to an elevated temperature, circulating means forpassing said fluid at said elevated temperature through said incomingbranch, said shell, said outgoing branch, said nozzle and part of saidchamber into said duct, recirculating means forming a return path forpart of said fluid from a downstream location in said duct to anupstream location at the end of said chamber remote from said duct intothe space between said layer and said nozzle, said elevated temperaturebeing high enough to activate said layer for injecting electrons intothe recirculated part of the fluid within said space, and collectormeans for said electrons positioned in said duct.

2. In an electric-current generator, in combination, a generallytoroidal shell having a substantially frustoconical inner peripheralwall of thermally conductive material forming a central chamber, saidwall being provided with an electron-emissive layer in said chamber,conduit means having an incoming branch and an outgoing branch openinginto the interior of said shell, said conduit means further including aduct forming an extension of said chamber beyond the narrower endthereof, said outgoing branch terminating in a nozzle extending intosaid chamber in the direction of convergence thereof and along thetoroidal axis of said shell in spaced relationship with said layer, asource of gaseous fluid connected to said conduit means, heating meansadjacent said conduit means for bringing said fluid to an elevatedtemperature, circulating means for passing said fluid at said elevatedtemperature through said incoming branch, said shell, said outgoingbranch, said nozzle and part of said chamber into said duct,recirculating means forming a return path for part of said fluid from adownstream location in said duct to an upstream location at the widerend of said chamber into the space between said layer and said nozzle,said elevated temperature being high enough to activate said layer forinjecting electrons into the recirculated part of the fluid within saidspace, and collector means for said electrons positioned in said duct.

3. In an electric-current generator, in combination, a generallytoroidal shell having an inner peripheral wall of thermally conductivematerial forming a central chamber, said wall being provided with anelectron-emissive layer in said chamber, conduit means having anincoming branch and an outgoing branch opening into the interior of saidshell, said conduit means further including a duct forming an extensionof said chamber, said outgoing branch terminating in a nozzle extendinginto said chamber along the toroidal axis of said shell in spacedrelationship with said layer, a source of gaseous fluid connected tosaid conduit means, heating means adjacent said conduit means forbringing said fluid to an elevated temperature, circulating means forpassing said fluid at said elevated temperature through said incomingbranch, said shell, said outgoing branch, said nozzle and part of saidchamber into said duct, said elevated temperature being high enough toactivate said layer for injecting electrons into the fluid passingthrough said space, and collector means for said electrons positioned insaid duct.

4. In an electric-current generator, in combination, a generallytoroidal shell having a substantially frustoconical inner peripheralwall of thermally conductive material forming a central chamber, saidwall being provided with an electron-emissive layer in said chamber,conduit means having an incoming branch and an outgoing branch openinginto the interior of said shell, said conduit means further including aduct forming an extension of said chamber beyond the narrower endthereof, said outgoing branch terminating in a nozzle extending intosaid chamber in the direction of convergence thereof and along thetoroidal axis of said shell in spaced relationship with said layer, asource of gaseous fluid connected to said conduit means, heating meansadjacent said conduit means for bringing said fluid to an elevatedtemperature, circulating means for passing said fluid at said elevatedtemperature through said incoming branch, said shell, said outgoingbranch, said nozzle and part of said chamber into said duct, saidReferences Cited in the file of this patent UNITED STATES PATENTSRudenberg June 18, 1929 Johnstone Dec. 2, 1958

1. IN AN ELECTRIC-CURRENT GENERATOR, IN COMBINATION, A GENERALLYTOROIDAL SHELL HAVING AN INNER PERIPHERAL WALL OF THERMALLY CONDUCTIVEMATERIAL FORMING A CENTRAL CHAMBER, SAID WALL BEING PROVIDED WITH ANELECTRON-EMISSIVE LAYER IN SAID CHAMBER, CONDUIT MEANS HAVING ANINCOMING BRANCH AND AN OUTGOING BRANCH OPENING INTO THE INTERIOR OF SAIDSHELL, SAID CONDUIT MEANS FURTHER INCLUDING A DUCT FORMING AN EXTENSIONOF SAID CHAMBER, SAID OUTGOING BRANCH TERMINATING IN A NOZZLE EXTENDINGINTO SAID CHAMBER ALONG THE TOROIDAL AXIS OF SAID SHELL IN SPACEDRELATIONSHIP WITH SAID LAYER, A SOURCE OF GASEOUS FLUID CONNECTED TOSAID CONDUIT MEANS, HEATING MEANS ADJACENT SAID CONDUIT MEANS FORBRINGING SAID FLUID TO AN ELEVATED TEMPERATURE, CIRCULATING MEANS FORPASSING SAID FLUID AT SAID ELEVATED TEMPERATURE THROUGH SAID INCOMINGBRANCH, SAID SHELL, SAID OUTGOING BRANCH, SAID NOZZLE AND PART OF SAIDCHAMBER INTO SAID DUCT, RECIRCULATING MEANS FORMING A RETURN PATH FORPART OF SAID FLUID FROM A DOWNSTREAM LOCATION IN SAID DUCT TO ANUPSTREAM LOCATION AT THE END OF SAID CHAMBER REMOTE FROM SAID DUCT INTOTHE SPACE BETWEEN SAID LAYER AND SAID NOZZLE, SAID ELEVATED TEMPERATUREBEING HIGH ENOUGH TO ACTIVATE SAID LAYER FOR INJECTING ELECTRONS INTOTHE RECIRCULATED PART OF THE FLUID WITHIN SAID SPACE, AND COLLECTORMEANS FOR SAID ELECTRONS POSITIONED IN SAID DUCT.